Polka-Dotted Horses? Cave Art May Not Be Fantasy

There are paintings beyond price in southwestern France in caves. Wall paintings still visible today date back to the Paleolithic period, more than 25,000 years ago. Over the years, scientists have disagreed about these ancient artists' depiction of animals. Were they realistic or perhaps were they pictures of imaginary creatures? For example, in caves in France, there are paintings of horses - black horses, brown horses, and then polka-dot horses. Where there really horses with a kind of Dalmatian-like coat in the ancient world? Professor Terry O'Connor of the University of York in England is one of the scientists who tried to find out. He joins me from the studio there. Welcome to our program.

TERRY O'CONNOR: Glad to be here.

WERTHEIMER: Now, you are an archaeologist and you specialize in human-animal relationships. Can you briefly describe what you and your colleagues did to try to figure out the mystery of the spotted horses?

O'CONNOR: Yeah, essentially what we were trying to do here was to find out whether we could in some way check whether the horse illustrations that the go - as you were saying - right back as much as 25,000 years in some caves, were accurate representations of what people were actually seeing or whether they had this really imaginary element to them. And the way we did that was simply to access bones of horses over the same date as the paintings from excavations, often in the same caves or in caves in the same area, and from those bones we were able to recover little scraps of DNA sequence that represent particular genes. And by very carefully targeting the right genes, what we've been able to do is to say, look, what can we show in here is we've got genes with a black coat color, and in some we've got genes with a brown coat color. And in just a few, half a dozen, we've got the genes in modern horses produce a spotted-colored coat.

WERTHEIMER: So, there really were polka-dotted horses?

O'CONNOR: There really were, yeah. So, people were drawing what they saw, which is fantastic for us.

WERTHEIMER: Now, why does it matter whether these paintings reflect reality or not?

O'CONNOR: Well, all kinds of reasons really. The very simple reason why we were very pleased with this result is that at least we've been able to show that a color coat characteristic, which for a long time people had said was a mutation that had arisen in domestic horses possibly quite recently, actually had very great antiquity. It goes before domestication of horses. But then, more to the point, some of the things that they're drawing are now extinct. So, nobody on earth today has ever seen a live mammoth. So, if the eyewitness accounts we have of them of the rather beautiful drawings of mammoths that turn up in some of these caves - and woolly rhinoceros, the same, you know - this gives us more confidence, if you like, to say, you know, all right, we can trust what these guys were drawing because we've been able to check, in the case of the horses, that the kind of coat colors and builds and so on that they were representing actually is consistent with what we see in the physical remains of the horses. But it gives us that bit more confidence therefore to say, yeah, that's probably what a woolly mammoth actually did look like.

WERTHEIMER: As I understand it, there is a very beautiful painting of a woolly mammoth in the same cave where the spotted horse painting is.

O'CONNOR: There is, yes. That's right. A mammoth is quite a widespread motif, actually. I had the pleasure last summer of visiting one of the Pictodoine(ph) caves at a place called the Grotto Riffiniac(ph), which deep down in the cave has the most beautiful friezes of mammoths and bison and things drawn on the walls and many of them on the ceiling. They're just line drawings, they're not colored like the horses that we were looking at. And basically, it's a piece of charcoal, a stick from the fire. And somebody's just stood there and drawn on the ceiling these wonderful, simple, but very lively, very sort of dynamic images. And standing there gazing at these really does make you, well, it's your point of contact I think.

WERTHEIMER: Professor Terry O'Connor is an archaeologist at the University of York in England. The study that he and his colleagues did about spotted horses was published this week in the Proceedings of the National Academy of Sciences. Professor O'Connor, thank you.